Receivers such as but not limited to battery-powered wireless content receivers in TVs, cameras, other hand held devices, and audio/video servers, which devices may include processors executing an operating system such as Windows CE®, can consume power to the point that the device battery can be quickly drained. Even wired devices should conserve power for energy conservation purposes. Accordingly, the present invention recognizes a need for power conservation.
The present invention further critically recognizes that the above need may be particularly acute in higher frequency wireless receivers such as 60 GHz receivers that operate in the wireless spectrum between 57 GHz and 64 GHz (hereinafter “60 GHz band”), which is unlicensed by the U.S. Federal Communications Commission to give organizations the opportunity, unfettered by excessive regulations, to use this spectrum for implementing wireless local area networks (LANs). The wireless LANs, in turn, can be used in a large number of applications owing to the characteristics of the 60 GHz spectrum, which include short range, high directivity (and, hence, inherent security), and large data bandwidth. Excessive power may be required, however, to permit the use of high frequencies.
Regardless of the application, the present invention makes the additional critical observations. A receiver that is not actively receiving may enter a lower power standby mode, in which some of the receiver's circuitry is deactivated to conserve power. When it is time for the receiver to process signals as indicated by the transmission of a pilot “control signal” from a sender, the receiver enters a full power mode. As understood herein, however, heretofore significant portions of the receiver circuitry have been required to remain energized in the standby mode to process directionless AC control signals to reconfigure the receiver to the full power mode, detracting from the utility of the standby mode. The AC control signals have been required to avoid unintentionally powering up other nearby quiescent receivers, which might otherwise detect a directionless control signal and leave the standby mode despite the fact that, no incoming signal is intended for the receiver. Having made the observations above, the invention herein is provided.